76 



SMITH'S INTERMEDIATE CHEMISTRY 



than 35.46 and none which was not a multiple of 35.46 by a whole 

 number. Clearly we shall find it convenient to accept 35.46 as the 

 unit or standard weight of chlorine for expressing the compositions 

 of its chemical compounds. Its use will enable us to state the 

 exact composition of any given compound by simply giving the 

 whole number (1, 2, 3, etc.) by which the basal weight 35.46 is to be 

 multiplied in the given case. 



Similarly, we take 1.008 as the unit weight of hydrogen and 16 

 as the unit weight of oxygen. By including volatile compounds of 

 other elements in our investigation, we can similarly pick out the 

 most convenient unit for each element. Those unit weights for 

 elements are often called also combining or reacting weights, and 

 still more frequently atomic weights (see p. 86). A complete 

 list of their values for all the known elements is given in a table 

 inside the rear cover of this book. These numbers will hereafter 

 be in constant use. 



The following table presents the results obtained from a larger 

 number of substances and gives their formulae (see p. 78) : 



